WO2014056426A1

WO2014056426A1 - Data transmission method

Info

Publication number: WO2014056426A1
Application number: PCT/CN2013/084848
Authority: WO
Inventors: 孙霏菲; 张园园; 徐家俊; 傅宜康
Original assignee: 联发科技（新加坡）私人有限公司
Priority date: 2012-10-08
Filing date: 2013-10-08
Publication date: 2014-04-17
Also published as: CN104737614A; US20180007717A1; US10149326B2; CN104737614B; US20150282213A1; US9807800B2

Abstract

The present invention provides a method for transmitting effective data in a mobile cellular network, comprising establishing an effective data link rather than establish an RRC connection. A specific resource pool is divided into a plurality of resource groups so as to indicate a data size level of to-be-transmitted data. A base station may allocate a proper UL grant to a terminal based on a received indication. Based on the allocated UL grant, the terminal may compare a data size of a granted transmission block and a data size of to-be-transmitted data. If the UL grant is large enough, the terminal transmits the to-be-transmitted data in the allocated UL resource, and otherwise, the terminal may try random access again. In another example, the terminal transmits a BSR message and as much data as possible. If there is data still needing to be transmitted, the base station may grant extra UL resource. In one example, a timer is further comprised, which is used by the terminal to determine whether it is necessary to wait for the extra UL grant from the base station. If the timer expires before the extra UL grant is received, the terminal may try a random access process again.

Description

Data transmission method

The present invention relates to a data transmission method, and more particularly to an efficient data transmission method for a mobile cellular network used in Machine Type Communication (MTC).

Background technique

Due to the development of MTC technology, many cellular MTC users have been added in the past few years. MTC introduces several new features and requirements for air interface optimization. 3GPP has optimized these new features and requirements in the Structural Analysis (SA) and Radio Access Network (RAN) working groups. Some common features have been pointed out in 3GPP TR 23.888 by 3 8 2, such as small data transmission, lower power consumption, time-controlled traffic, infrequent traffic ) Wait. RAN2 has studied RAN enhancement for MTC, and RAN1 is also studying low-cost MTC terminals based on LTE.

FIG. 1A is a schematic diagram of a random access procedure (hereinafter referred to as RA) in the prior art. Figure 1B is a schematic diagram of MAC random access response information. In 3GPP TS 36.300, a random access procedure is implemented when a UE (user equipment, also referred to as a terminal) initially accesses the network, and the four steps based on the content of the random access procedure are described as follows: UE based base station The configuration of (Node B, or eNB), based on the system information, selects a preamble sequence and serially transmits the prefix on the time-frequency resources configured in the system information. The random access response (MSG 2) conveys information including at least an RA prefix identifier, a timing advance command, an initial UL grant, and a temporary C-RNTI allocation, as shown in FIG. 1A. . The UE transmits a scheduled transmission (a third message, denoted MSG 3) through the initial UL grant (shown in Figure 1B) delivered in the second message (MSG 2). For initial access, the MSG 3 is used to deliver an RRC connection request generated by a Radio Resource Control Protocol (RRC) layer, where the RRC connection request includes at least a NAS UE identifier. Competitive Resolution (MSG 4) is used to convey contention resolution. The UE transmits the HARQ feedback only when it detects the UE identifier provided by the MSG 3 in the contention resolution message.

Signaling overhead compared to data packet data

(PDCCH/MAC CE/RRC message) is relatively larger. And how to transfer small data more efficiently with less overhead is an important issue.

Summary of the invention

In view of this, the present invention provides a method of efficiently transmitting data in a mobile cellular network.

The present invention provides an effective data transmission method, including receiving, by a terminal, broadcast information from a base station, where The broadcast information includes at least one specific resource pool and at least one non-specific resource pool; and wherein when the terminal meets the at least one condition, the terminal uses the at least one specific resource pool to perform a random access procedure for transmitting data.

In an embodiment, some non-specific resource pools are random access procedures used by terminals to implement RRC connection establishment (re-establishment), and specific resource pools are used for random access procedures for transmitting traffic data without RRC connection. . The resource pool may be divided into different prefix sequence sets or different composite time-frequency domain resource block sets or a combination of different prefix sequence and composite time-frequency resource blocks. The data to be transmitted includes at least terminal identification information, routing information of the core network, and traffic data packets from the application layer.

In an embodiment, the base station may configure at least one condition to support traffic data transmission without RRC connection, or may pre-define conditions in a technical specification, wherein the at least one condition may be at least one of the following conditions: The amount of data of the traffic data packet transmitted from the application layer is greater than zero; the amount of data to be transmitted in the terminal is less than a threshold; the channel condition is better than a threshold; the delay requirement is less than a threshold; and the expected data arrival interval is greater than A threshold and so on.

The effective data transmission method as described above, further determining, by the terminal, whether the terminal satisfies the traffic data transmission condition without the RRC connection, and if the terminal satisfies the condition, the terminal selects a resource from the specific resource pool, Traffic data transmission based on no RRC connection. If the terminal does not satisfy the condition, the terminal transmits the traffic data after establishing an RRC connection.

In another embodiment, the terminal may use some specific resource pool to inform the base station of some information or features of the terminal, such as channel conditions (path loss/coverage), traffic data packet size, expected data arrival interval, delay. Claim. After the base station knows the above information or features as early as possible, the base station can give an appropriate response, for example: allocating a UL grant, wherein the grant considers the size of the service data; and transmitting an UL grant to the base station using an appropriate response, wherein the UL grant is based on the The terminal informs the base station of the channel condition.

The present invention provides a terminal detecting apparatus, including: a transmitting apparatus, transmitting a prefix sequence to a base station on a time-frequency domain resource block, wherein the prefix sequence and/or the time-frequency domain resource block is from a specific resource pool Select from a resource group.

In one embodiment, the terminal calculates channel conditions, compares the calculated channel conditions to a threshold, and selects a set of resource groups from the particular resource pool based on channel conditions and predefined mapping rules.

In another embodiment, the terminal calculates the amount of data to be transmitted, matches the value of the calculated data amount with a data amount level, and selects a resource from the specific resource pool according to a predefined rule. group. The data to be transmitted includes at least terminal identification information, a traffic data packet from the application layer, and routing information of how the traffic data packet of the application layer is transmitted through the core network and the serving gateway. For example, the routing information is an end point related to a PDN connection, or a bearer of the SGW, where the bearer is, for example, a bearer Source ID. The above information may be initially provided by the base station to the terminal. Or the routing information can include a connection ID, a token, and a signature. The mapping between the connection ID and the context of the terminal and the mapping between the connection ID and the SGW can be stored in the base station.

In one embodiment, the terminal calculates the amount of data to be transmitted, and matches the calculated amount of data with a data amount level. If the calculated data amount is greater than or equal to a threshold, the terminal establishes an RRC connection and transmits traffic. data.

In another embodiment, the terminal receives the prefix sequence transmitted by the terminal on a time-frequency domain resource block, and the base station acquires the amount of data to be transmitted by the terminal, allocates UL resources to the terminal according to the amount of data to be transmitted, and Transmitted in a random access response. After the terminal receives and decodes the random access response, the terminal determines whether the authorized transmission block (TB) data amount is greater than or equal to the amount of data to be transmitted. If the amount of the transferred block data to be authorized is greater than or equal to the amount of data of the data to be transmitted, the terminal transmits the to-be-transmitted data in the allocated UL resource. If the authorized transport block is greater than or equal to the amount of data to be transmitted, the terminal multiplexes a plurality of MAC SDUs in the MAC PDU, wherein the MAC SDU includes data available for transmission, and the terminal is in the MSG 3 buffer The MAC PDU is stored in the (third message buffer), and the MSG 3 is transmitted in the allocated UL resource. If the amount of the transferred transport block data is less than the amount of data that can be used to transmit data, the BSR report is triggered; at the same time, the terminal encapsulates the terminal identification information, the core network routing information, the BSR MAC control element, and the traffic data packet from the application layer. Priority multiplexing is performed with strict decrement until the UL grant is exhausted, and the terminal stores the MAC packet data unit in the MSG 3 and transmits the MSG 3 in the allocated UL resource. If the amount of transport block data is less than the amount of data available for transmission, the terminal re-attempts the random access procedure.

In one embodiment, after the base station resolves the contention resolution for the terminal, the base station authorizes an additional UL resource to the terminal for residual data transmission, wherein the UL grant is based on the received BSR from the terminal. The remaining data is, after the previous UL authorization is exhausted, the remaining terminal identification information for multiplexed with strict decrement priority, core network routing information, BSR MAC control element, and traffic data packet from the application layer. The data. Alternatively, after the terminal successfully resolves the dispute, if the terminal receives an additional UL grant, the terminal uses the resource to transmit the remaining data. If there is residual data in the terminal, but no additional UL grant is received from the base station during an additional UL grant timer, the terminal re-attempts the random access procedure. After successfully decoding the remaining data from the terminal, the base station transmits an acknowledgement message to the terminal, and merges the remaining data after the previous received data, and transmits the traffic data packet to a suitable server through a service gateway. .

The effective data transmission method provided by the present invention can save overhead, thereby saving power consumption and accelerating communication. DRAWINGS

FIG. 1A is a schematic diagram of a random access procedure in the prior art.

Figure 1B is a schematic diagram of MAC random access response information.

2 is a schematic diagram of a wireless communication system 100 in accordance with an embodiment of the present invention.

FIG. 3 is a schematic diagram of a protocol stack and partial functional modules of a UE and an eNB according to an embodiment of the present invention.

4A, 4B, 4C, and 4D are schematic flow charts of a data transmission method according to an embodiment of the present invention. FIG. 5 is a schematic diagram of a method for selecting a random access resource for a terminal without RRC connection data transmission according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a method for a base station to transmit data without an RRC connection according to an embodiment of the present invention. detailed description

In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail in conjunction with the embodiments and drawings. The illustrative embodiments of the present invention and the description thereof are intended to explain the present invention, but are not intended to limit the invention. The term "component", "system", and apparatus used in this application may be an entity associated with a computer, which may be hardware, a combination of hardware and software, or software. Certain terms are used throughout the description and claims to refer to particular components. Those skilled in the art will appreciate that manufacturers may refer to the same component by different nouns. The present specification and claims do not use the difference in name as the manner of the group grouping, but the difference in function of the components as the criterion for distinguishing. The words "including" and "including" as used throughout the specification and claims are intended to be interpreted as "including but not limited to". In addition, the term "coupled" is used herein to include any direct and indirect electrical connection. Indirect electrical connections include connections through other devices.

2 is a schematic diagram of a wireless communication system 100 that includes base stations 101 that serve different types of terminals 102 and 103, in accordance with an embodiment of the present invention. Different types of terminals, for example, terminal A 102 and terminal B 103, may have different types of traffic, such as a big data flow or a small data flow, or a human-to-human (H2H) device or machine type communication (Machine). Type Communication, MTC) device. Different types of terminals can be served by the same base station in the same geographical area or cell. While the above system architecture is by way of example only, the invention is not limited to any particular wireless communication system.

FIG. 3 is a simplified block diagram of the UE 141 and eNB 142 protocol stacks. The UE 141 has a physical layer stack (PHY), a MAC layer (MAC), a radio link control (RLC), a Packet Data Control Protocol (PDCP), and a Radio Resource Control (RRC). . The eNB 142 has a corresponding protocol stack that communicates with the UE 141, including PHY, MAC, RLC, PDCP and RRCo

The UE 141 and the RF transceiver module 150 are coupled to the antenna 171, and the RF transceiver module 150 receives the RF signal from the antenna 171, converts it to a baseband signal, and transmits it to the processor 151. The RF transceiver 150 also converts the baseband signal received from the processor 151 into an RF signal and transmits it to the antenna 171. The processor 151 processes the received baseband signal and activates different functional modules to implement the functions in the UE 141. Memory 152 stores program instructions and data to control the operation of UE 141. Fig. 3 further shows a schematic diagram of four functional modules 153 to 156 embodying an embodiment of the present invention. The link connection module 153 establishes a connection with a plurality of points or a plurality of eNBs to support data transmission. The Configuration module 154 is used to store configurations related to a particular resource pool. Decoding module 155 decodes the received data stream. The detection module 156 detects if the UE satisfies at least one predefined specific condition.

The eNB 142 has an RF transceiver module 160, wherein the RF transceiver module 160 is coupled to the antenna 172 for receiving RF signals from the antenna 172, converting them to baseband signals, and transmitting them to the processor 161. The RF transceiver module 160 also receives the baseband signal from the processor 161, converts it to an RF signal, and transmits it to the antenna 172. The processor 161 processes the received baseband signals and activates different functional modules to implement the functions in the eNB 142. Memory 162 stores program instructions and data to control the operation of eNB 142. Figure 3 shows four functional modules 163 through 167 in the eNB 142 embodying an embodiment of the present invention. The link connection module 163 manages the connections between the eNBs and between the UE and the eNb. The configuration module 164 is used to store the configuration of the resource pool allocation and information related to the resource pool configuration. Encoding module 166 encodes the data to be transmitted. The detecting module 167 detects whether the UE satisfies at least one predefined specific condition, or determines whether the UE satisfies the at least one predefined specific condition by receiving the corresponding information from the UE, thereby determining the subsequent operation, for example, for the use of the specific resource pool. UL authorization, etc.

4A, 4B, 4C, and 4D are schematic flow charts of a data transmission method according to an embodiment of the present invention. As shown in FIG. 4A, the base station can broadcast system base station system information (SI), the system information including the configuration of the random access transmitted to the terminal and other channel information. In this configuration, there may be several separate resource pools, which may pass different sets of prefix sequence sets or different composite time-frequency region sets or different prefix sequences and The combination of the composite time-frequency domain resource blocks is separated. Some of the resource pools are random access procedures used by the terminal for RRC connection establishment (re-establishment), and the other specific resource pool is used by the terminal for implementing data transmission without establishing an RRC connection. Random access process.

In other embodiments, the terminal may use some resource pools for notifying the base station of some messages or features about the terminal, such as channel conditions (eg, path loss or coverage, etc.), data volume of the traffic data packet. , expected data arrival period (tim _{e 0} f arri _va l), delay request, etc. With these previous information, the base station can An appropriate response is provided, such as considering the amount of data of the traffic data packet to allocate the UL grant, and transmitting the UL grant to the terminal using the appropriate resource pool based on the channel conditions notified by the terminal.

In another embodiment, if the base station wants to support a data transmission method without RRC (non-RRC) connection, the base station can configure some conditions for the terminal so that the terminal can attempt to transmit data without establishing (re-establishing) the RRC connection. The above conditions may be a combination of at least one of the following conditions:

The traffic data packet from the application layer that needs to be transmitted is greater than zero;

The data to be transmitted at the terminal is less than a threshold;

The channel condition is better than a threshold;

The delay requirement is less than a threshold;

The expected data arrival interval (interval) is greater than a threshold.

Alternatively, the above rules may be predefined in a specification.

The data to be transmitted includes at least terminal identification information, routing information of the core network, and traffic data packets from the application layer. The terminal identification information may be a terminal identifier or information distinguishable from other terminals. Routing information is information used by the core network to route traffic data packets through the service gateway to the appropriate server.

In another embodiment, if the base station can support a terminal with special requirements or special conditions, for example, the terminal has extreme channel conditions, or has special delay requirements, the base station can be configured in the terminal in combination with one or more of the above conditions. . That is to say, only terminals that meet these conditions can use other specific resource pools, and are not limited to no RRC connection. Specifically, for example, in the case of an RRC connection, the base station can configure the terminal in combination with one or more of the above conditions, so that the terminal can use other specific resource pools in accordance with one of the above conditions.

In order to effectively schedule a terminal and allocate resources by a base station, resources in a specific resource pool (a prefix sequence or a composite time-frequency domain resource block or a combination of a prefix sequence and a composite time-frequency domain resource block) may be divided into several groups, where Each group is used to indicate a size level to be transmitted. The resource groupings in a particular resource pool can be configured by the base station. Alternatively, resource groupings in a particular resource pool may be pre-defined in the technical specifications.

The base station can configure an additional mapping rule to indicate how each resource packet in a particular resource pool corresponds to the data volume level of the data to be transmitted. In another embodiment, this additional mapping rule is how each resource group in a particular resource pool corresponds to a channel condition level. Alternatively, the mapping rule can be predefined in the technical specification.

The terminal receives system information from the base station, and obtains configuration for the random access procedure therefrom, or obtains some predetermined rules from the technical specifications. The terminal determines whether there is a specific resource pool, and if there is a specific resource pool, the terminal acquires the conditions that need to be met by using the specific resource pool from the system information. Based on acquired conditions, terminal It can be judged whether or not all conditions are satisfied, for example, the terminal can calculate the amount of data of the data to be transmitted, measure channel conditions or/and estimate the data arrival interval, and the like. If the terminal meets all the conditions, the resources in that particular resource pool can be used.

The terminal calculates a value of the amount of data of the data to be transmitted, and matches the calculated value to a certain data amount level based on a predetermined rule. The terminal finds a corresponding one of the specific resource pools according to the matched data volume level, where a corresponding one of the specific resource pools may indicate a data volume level packet of the data to be transmitted, and the terminal may select a prefix sequence from the packet and / or time-frequency domain resource blocks. The terminal then transmits the selected prefix sequence on the selected time-frequency domain resource block.

In another embodiment, the terminal receives a PSS/SSS downlink broadcast channel (eg, PBCH or PDCCH or PDSCH convey SIB) and/or other physical channel/signal or measurement (eg, reference signal) Receive Signal Received Power (RSRP), which knows the downlink channel conditions. Based on the downlink channel condition, the terminal matches the channel condition (path loss/coverage condition) to the data volume level according to a predefined rule, and selects a prefix sequence and a time-frequency domain resource block from a group of the specific resource pool, where the packet Used to indicate channel conditions (path loss/coverage conditions) based on this extra matching rule. The terminal then transmits the selected prefix sequence on the selected time-frequency domain resource block.

Alternatively, if the terminal does not satisfy the condition for transmitting data without RRC connection establishment (re-establishment), the terminal may fall back to establish an RRC connection, using a resource pool for establishing an RRC connection to implement random access process.

The base station receives the random access prefix sequence on the time-frequency domain resource block and determines whether the prefix and/or the synthesized time-frequency domain resource block is in the configured or predefined specific resource pool. In an embodiment where a specific resource pool is used for no RRC connection, if the prefix and/or the synthesized time-frequency domain resource block is in the specific resource pool, the base station may know that the terminal attempts to establish (re-establish) without RRC connection. Transmit traffic data. In another embodiment, the terminal attempts to inform the base station of its channel conditions (path loss/coverage conditions). In addition, the base station may be based on configured or pre-defined or configured mapping rules, such as data level or channel conditions (path loss/coverage conditions) of data transmittable by the terminal, through prefix sequence and/or synthesized time-frequency domain resources. The resource group in which the block is located to obtain the data volume level information of the data to be transmitted. After knowing the level of data to be transmitted, the base station may allocate a UL grant to the terminal for the terminal based on the amount of data, and transmit it in an access response to the terminal. In an embodiment, the data volume level may be a data volume level of data that the terminal can transmit.

Alternatively, in the random access response, the base station may allocate a UL grant to the terminal that is smaller than the amount of data to be transmitted obtained from the prefix sequence and/or the time-frequency domain resource block. In another embodiment, the base station uses the appropriate downlink resource pool and transmits the allocated UL grant based on the data volume level, wherein the data volume level is used to indicate channel conditions (path loss/coverage conditions). The channel condition may be a downlink channel condition, wherein the downlink channel condition may be estimated by the terminal receiving the PSS/SSS and/or other downlink channels/signals. By using the downlink channel condition, the base station can trade off the reliability and the access overhead when transmitting the downlink channel. On the other hand, the base station can receive the random access prefix on the time-frequency resource block transmitted by the terminal. The sequence (for example, assuming that the terminal is transmitted at full power), and estimating the uplink channel condition (path loss/coverage condition). Estimation based on channel conditions (path loss/coverage conditions), and considering robustness And system access overhead, the base station can arrange the appropriate UL grant to enable the terminal to transmit UL data.

The terminal may receive a response with the access from the base station. If the random access response includes an identifier corresponding to the transmitted random access prefix, the terminal can determine whether the data amount of the authorized transport block (TB) in the random access corresponding is equal to or greater than the amount of data to be transmitted. If the data volume of the authorized transport block is equal to or greater than the data volume to be transmitted, the terminal may transmit all data to be transmitted to the base station, where the data to be transmitted includes at least terminal identifier information, routing information of the core network, and the application. The layer's traffic data packet.

In an LTE/LTE-A system, a terminal may transmit a plurality of MAC Service Data Units (SDUs) in a Medium Access Control (MAC) Packet Data Unit (PDU), where the MAC SDU includes all Data to be transmitted. The terminal stores this MAC packet data unit in the MSG 3 Buffer and transmits the MSG 3 in the UL grant.

If the amount of data of the authorized TB is less than the amount of data to be transmitted, the terminal can retry the random access procedure. Alternatively, if the amount of data of the authorized TB is greater than the amount of data to be transmitted, the terminal may assume that the base station is temporarily unable to support data transmission based on the RRC-free connection, and fall back to the general random access procedure to perform RRC connection establishment ( Re-establish) . Alternatively, as shown in FIG. 4B, if the amount of data of the authorized TB is smaller than the amount of data to be transmitted, the terminal may trigger a Buffer State Report (BSR), and the terminal may strictly decrement the priority in the MAC PDU. The transmission terminal identification information, the routing information of the core network, the BSR MAC control element, and the traffic data packet from the application layer are not used until the UL authorization is exhausted. The terminal stores the MAC PDU in the MSG 3 and transmits the MSG 3 in the allocated UL resource.

The base station receives and decodes the data transmitted by the terminal. If the base station performs the UL grant based on the data level of the data to be transmitted indicated by the terminal in the random access response, or the amount of BSR data reported by the terminal is zero, the base station can assume all traffic. The data packet has been completely transferred. The base station can transmit a contention resolution message to the terminal and pass the traffic data packet to the appropriate server through the service gateway.

Alternatively, if the base station does not allocate a sufficiently large UL grant to the terminal in the random access response, or is non-zero The BSR is triggered and transmitted in the MSG 3, then the base station can authorize an additional UL resource for the terminal, and the terminal transmits the remaining data after completing the contention resolution, wherein, as shown in FIG. 4C, the remaining data can be After the previous UL grant is exhausted, the terminal identification information, the routing information of the core network, the BSR MAC control element, and the remaining data of the traffic data packet from the application layer are strictly decremented.

After the terminal successfully completes the contention resolution, if the terminal has transmitted all the data packets, the terminal assumes that all data has been successfully received by the base station, and the terminal will return to the idle mode. Alternatively, as shown in FIG. 4D, after the terminal successfully completes the contention resolution, if the terminal receives an additional UL grant within the additional UL grant timer, the terminal may transmit the remaining data to the base station using the UL resource. Alternatively, if there is residual data at the terminal, but no additional UL grant is received from the base station within the additional UL grant timer, the terminal may retry the random access procedure.

If the base station transmits additional UL resources to the terminal, the base station will receive and decode the remaining data on the UL resource. After successfully decoding the data, the base station can transmit an acknowledgment (ACK) message to the terminal, combine the remaining data with the previously received transmitted data, and transmit the traffic data packet to the appropriate server through the serving gateway.

Some types of traffic in the network are typically downlink (Down Link, DL, which can be referred to as downlink or downlink) and uplink (UL, which can be referred to as uplink or uplink), and Also some applications are typically heavy access overhead in UL. For example, based on the traffic specificity specified in 3GPP TR 37.868, 3GPP TR 36.888 gives the traffic model of the MTC, where UL is used for low-cost MTC in the case of the UL level of the second and minute levels. The amount of packet data is 1000 bits. In RP-121282, the Vodafone Group gives typical traffic for smart meters. Typical traffic for this smart meter is low latency, low data rate packets, such as 100 bytes/message in UL, and The DL is 20 bytes/message. In these cases, the amount of packet data is comparable to the signaling overhead, such as the signaling overhead for RRC connection setup (re-establishment). On the other hand, the time used to establish an RRC connection may be longer than the packet transmission time. This will reduce the performance of the entire network when a large number of end users are on the network. Therefore, an efficient data transmission method is necessary. At the same time, if the terminal can transmit small data without transmitting/receiving a large amount of control signaling, the power consumption can be further reduced.

The random access procedure is implemented for the following procedures: RRC Connection Setup (Re-establishment) Process, handover, or DL or UL data arrival in the RRC_CONNECTION state. Random access is a necessary process for initial connection and data transmission for all terminals. In order to transmit data with higher efficiency, data can be transmitted without establishing an RRC connection. However, in order to transmit data more efficiently, how to report the amount of data to be transmitted by the terminal to the base station is the first step. How the base station assigns the appropriate UL grant to the terminal is also a problem to be solved. Another key question is how to The data is transmitted by the terminal without establishing an RRC connection. Furthermore, a complete fall back mechanism is required to guarantee data transmission, for example, what can be done if the base station does not allocate a sufficiently large UL resource terminal at the beginning, and if the terminal further requests UL grant, how can the base station Reply and so on.

In one embodiment of the invention, the base station can broadcast system base station system information including configuration of random access to the terminal and other channel information. In this configuration, there may be several separate resource pools, which may be through different prefix sequence sets or different composite time-frequency domain resource blocks.

(time-frequency region) A set or a combination of different prefix sequences and composite time-frequency domain resource blocks. Some resource pools (that is, non-specific resource pools) are random access procedures used by terminals to implement RRC connection (re), and others are specific resource pools for random access procedures for transmitting traffic data without RRC connection. Further, in order to effectively schedule the terminal and allocate resources by the base station, the resources in the specific resource pool (prefix sequence or combined time-frequency domain resource block or prefix sequence and combined combination of synthesized time-frequency domain resource blocks) may be divided into several groups, and Each group indicates a data volume level of data to be transmitted. Resource packets in a particular resource pool can be configured by the base station. Alternatively, resource groupings in a particular resource pool can be pre-defined in the technical specifications.

The base station configures additional mapping rules to indicate how each resource packet in a particular resource pool corresponds to the data volume level of the data to be transmitted. Alternatively, the mapping rule can be predefined in the technical specification.

The present invention provides an efficient method and apparatus for transmitting data, as shown in FIG. FIG. 5 is a diagram of a terminal for selecting a random access resource for RRC-free data transmission according to an embodiment of the present invention. On the base station side, the base station can broadcast the configuration information and the data transmission condition to the terminal, and then receive the random access prefix from the terminal, and acquire the data volume level of the terminal. Finally, if the terminal attempts to perform data transmission without the RRC connection, The terminal is assigned a UL grant based on the acquired data volume level.

Corresponding to FIG. 5, FIG. 6 is a configuration apparatus for a base station for data transmission without an RRC connection according to an embodiment of the present invention. First, the terminal reads the configuration and conditions obtained from the base station, and then determines whether the terminal satisfies all data transmission conditions without the RRC connection, and then transmits the resource with a prefix to the base station to indicate the amount of resource data required by the terminal based on the configuration information. . Specifically, the terminal receives system information from the base station, and acquires configuration information or pre-defined rules in some technical specifications from the base station. The terminal determines whether there is a specific resource pool and if there is a specific resource pool, the terminal acquires the transmission condition to use the specific resource pool described above.

Embodiments of the present invention are described in detail below with reference to FIGS. 5 and 6. The base station can configure two separate resource pools, one for the normal random access procedure for RRC connection setup (re-establishment) and another for the random access procedure for data transmission without RRC connection. For example, for a resource pool and a specific resource pool used for a normal random access procedure, the prefix sequence root value rootSequencelndex may be set to 0 and respectively. 500, but the two resource pools share the same time-frequency resource block configuration with prach-ConfigInfo of 20. Alternatively, the normal resource pool and the time-frequency resource block configuration prach-ConfigInfo of the specific resource pool are set to 0 and 20, respectively, but share the same rootSequencelndex to be 0. Alternatively, the normal resource pool and the prefix of the specific resource pool rootSequencelndex are set to 0 and 500, respectively, and the prach-ConfigInfo is set to 0 and 20, respectively. Alternatively, another method of separating the prefix resources is normal and the specific resource pool shares the same prefix sequence root value rootSequencelndex, but the normal resource pool is the first 32 sequences, and the specific resource pool is the 64 sequences immediately following the normal resource pool. .

The condition for data transmission without RRC (non-RRC) connection is alternatively configured by the base station, and the condition may be pre-defined in a specification, and the terminal attempts to establish without re-establishment in the RRC connection. ) and transfer data. The above conditions may be a combination of at least one of the following conditions:

The traffic data packet from the application layer that needs to be transmitted is greater than 0;

The data to be transmitted of the terminal is less than a threshold, for example, 125 bytes;

The channel condition is better than a threshold, for example, the path loss is less than Pmax;

And the expected data arrival interval is greater than a threshold, such as 320ms.

According to an embodiment of the present invention, a specific resource pool can be divided into 12 groups, and Table 1 gives a rule of how each resource group in a specific resource pool is mapped to a data amount level according to an embodiment of the present invention. The rootSequencelndex is 500 in a specific resource pool and the number of prefix sequences in a specific resource pool is 64. The prefix sequence is divided into 4 groups and each group has 64/4 = 16 sequences. The prefix group N is generally composed of the (N+1)~16x(N+l) sequences starting with rootSequencelndex 500. Table 2 depicts the packet data level within the maximum amount of packet data supported by 125 bytes.

Table 1: Mapping rules for resource groups and data volume levels in a specific resource

(For example, the FDD PRACH configuration index with 4 prefix groups 10 subframes {2, 5, 8})

Table 2: Packet data volume levels

Index data packet size index data packet size

(BS) value [byte] (BS) value [byte]

0 BS = 0 6 28 < BS <=37

1 0 < BS <= 10 7 37< BS <= 50

2 10 < BS <= 14 8 50 < BS <= 64 3 14 < BS <= 17 9 64<BS<=96

4 17 < BS <= 21 10 96<BS<=125

5 21< BS <= 28 11 BS>125 In another embodiment, the number of resource groups in the special resource pool can be configured by the base station. One or more rootSequencelndex and/or one or more prach-ConfigInfos are configured in a particular resource pool. In one embodiment, one or more rootSequencelndex and/or one or more prach-ConfigInfos are matched to a data volume level, wherein the matching is based on rules for how each resource group matches the data volume level. In another embodiment, the pool of physical resources in a prach-ConfigInfo can be further divided into a number of resource groups. And each resource group with the same or different rootSequencelndex is matched to the data volume level. A case of the PRACH-Config message element is disclosed below. PRACH-ConfigSpecial is configured in the PRACH-Config IE to transmit RootSequenceGroupNum and prach-ConfigInfoNum before one or more rootSequencelndex and prach-ConfigInfo.

The following examples are schematic elements of a Prach configuration (PRACH-Config) in accordance with an embodiment of the present invention.

PRACH-Config message element

- ASN1START

PRACH-ConfigSIB: SEQUENCE {

rootSequencelndex INTEGER (0..837) _;

prach-Configlnfo PRACH-ConfigInfo

PRACH-Config:: = SEQUENCE {

rootSequencelnde? INTEGER (0..837) _;

prach-Configlnfo PRACH-Configlnfo OPTIONAL - Need ON

PRACH-ConfigSCell-rlO: SEQUENCE {

prach-Configlndex-r 10 INTEGER (0..63)

PRACH-ConfigSpecial:: = SEQUENCE {

RootS equenceGroupNum INTEGER (0..16),

OPTIONAL - Need ON

rootSequencelndex- 0 INTEGER (0..837), OPTIONAL - Need ON rootSequencelndex- 1 INTEGER (0..837), OPTIONAL - Need ON prach- ConfiglnfoNum INTEGER (0..16),

OPTIONAL - Need ON

prach-Configlnfo-O PRACH-Configlnfo OPTIONAL - Need ON prach-ConfigInfo- 1 PRACH-Configlnfo OPTIONAL - Need ON PRACH-ConfigInfo:: = SEQUENCE {

prach-Configlndex INTEGER (0..63),

highSpeedFlag BOOLEAN,

zeroCorrelationZoneConfig INTEGER (0..15),

prach-FreqOf set INTEGER (0..94)

- The ASN1STOP terminal receives system information from the base station and obtains configuration for the random access procedure or obtains some pre-defined rules from the technical specifications. The terminal determines whether there is a specific resource pool, and if there is a specific resource pool, the terminal obtains the conditions that need to be met from using the specific resource pool from the system information. Based on the acquired conditions, the terminal can judge whether it satisfies all the conditions, for example, the terminal can calculate the amount of data of the data to be transmitted, measure the channel condition or / and estimate the data arrival interval and the like. If the terminal meets any of all the conditions, the resources in that particular resource pool can be used. In an embodiment of the present invention, the terminal calculates the data volume of the data to be transmitted, where the data to be transmitted includes terminal identification information (for example, terminal ID or different information as other terminals), routing information of the core network (for example, for Packet routing NAS information) and traffic data packets from the application layer. Those skilled in the art can understand that the terminal identification information can also be terminal identification or other identification information. Routing information is information used by the core network to route traffic data packets through the service gateway to the appropriate server. The terminal also measures path loss and estimates the expected data arrival interval. For example, the amount of data to be transmitted is calculated to be equal to 15 bytes, which is less than the threshold of 125 bytes, or the path loss is less than Pmax; or the next data packet is expected to arrive at 400ms. The terminal can use the resource pool to implement a random access procedure for the RRC connection setup (re-establishment) process, and to implement a random access procedure as other terminals.

If the terminal satisfies any one or more conditions required to transmit data without all RRC connections, the terminal can perform a random access procedure for transmitting data without connection. The terminal calculates a value of the amount of data of the data to be transmitted, and matches the calculated value to a certain data amount level based on a predetermined rule. The terminal finds a corresponding one of the specific resource pools according to the matched data volume level, and can indicate a data volume level packet of the data to be transmitted, and select a prefix sequence and/or a time-frequency domain resource block from the packet. The terminal then transmits the selected prefix sequence on the selected time-frequency domain resource block. For example, the amount of data to be transmitted calculated by the terminal is 15 bytes, and the terminal attributes the amount of data to be transmitted to index 3 according to Table 2. According to Table 1, the prefix sequence can be selected from the prefix group 1, and transmitted in the subframe 2.

Alternatively, if the terminal does not meet any of the foregoing conditions, or the application layer does not have a traffic data packet to be transmitted, the terminal retreats to establish an RRC connection. For example, the amount of data to be transmitted is calculated to be equal to 127 bytes, which is greater than the threshold 125. The byte is large, or the path loss is greater than Pmax; or the next data packet is expected to arrive at 100ms. Terminal A resource pool can be used to implement a random access procedure for the RRC connection setup (re-establishment) process, and to implement a random access procedure as other terminals.

The base station receives the random access prefix sequence on the time-frequency domain resource block and determines whether the prefix and/or the time-frequency domain resource block is in the configured or predefined specific resource pool. If in this particular resource pool, the base station can know that the terminal is attempting to transmit traffic data without an RRC connection setup (re-establishment). The base station may also transmit data levels of data to be transmitted through the prefix sequence and/or the time-frequency domain resource block based on configured or predefined mapping rules. Knowing the data volume level, the base station may allocate the UL grant to the terminal in the access response to the terminal based on the data volume level. According to an embodiment of the invention, the base station receives the transmitted prefix sequence from the terminal in subframe 2. Since the prefix sequence is selected from the prefix sequence group 1 and transmitted in the subframe 2, according to the mapping rule of Table 1, the packet data amount level is indicated as index 3. As a result, the base station acquires the packet data amount level as 14 < BS <= 17 bytes, according to Table 2. Therefore, the base station allocates a UL grant capable of carrying a data packet of 18 bytes for the data amount of the data packet, which is larger than the 17 bytes requested by the terminal. The base station multiplexes the UL grant capable of carrying the 18-byte data packet in the random access corresponding MAC PDU, and transmits it to the terminal by the base station. As shown in the MAC random access response diagram of Figure 2, the MAC PDU also includes the R/Timing Advance Command/Temporary C-RNTI as shown in Figure 2.

The terminal receives the random access response from the base station, where the random access response transmitted by the base station corresponds to the transmitted prefix sequence, and the terminal compares whether the authorized TB data volume can adapt to all data to be transmitted. For example, if 15 bytes is the amount of data to be transmitted, and the UL resource allocated by the base station is greater than 15 bytes, the terminal may transmit all the data to be transmitted to the base station, where the data to be transmitted includes at least the terminal identifier information and the route of the core network. Information and traffic data packets from the application layer. In the LTE/LTE-A system, multiple MAC Service Data Units (SDUs) may be included in a Packet Data Unit (PDU), and the terminal may The MAC SDU is multiplexed in the MAC PDU, where the MAC SDU contains all the data to be transmitted, and the MAC PDU is stored in the MSG 3 buffer, and the MSG 3 in the allocated UL resource is transmitted.

The base station receives and decodes data from the terminal. Since the base station schedules the UL grant based on the data level of the data to be transmitted, the base station can assume that all the traffic data packets have been completely transmitted, and then the base station can transmit the contention resolution message to the terminal, and the traffic data. The packet is passed to the core network and delivered to the appropriate server through the service gateway.

In other words, the base station can reply to the random access response using a smaller UL grant, which is smaller than the amount of data to be transmitted, wherein the UL grant is selected and decoded from the selected prefix sequence and/or the time-frequency domain resource block. For example, when the base station acquires a request with a data packet level of 14<BS<=17 bytes, the base station allocates one can bear The amount of TB data is equal to 10 bytes of UL grant.

Correspondingly, the terminal decodes the random access response to obtain a UL grant with a data amount smaller than the amount of data to be transmitted, and the terminal can re-select the resource from the group of the specific resource pool and retry the random access procedure. For example, the terminal obtains a UL grant with a TB data volume of 10 bytes by decoding the random access corresponding, wherein 10 bytes are smaller than the data volume to be transmitted is 15 bytes, and the terminal will re-select from the group of the specific resource pool. Resources, and retry the random access process.

Alternatively, when the terminal finds that the authorized TB data amount is 10 bytes, and 10 bytes is smaller than the data to be transmitted 15 data amount 15 bytes, the terminal may assume that the base station does not support data transmission based on the RRC-free connection, and fall back to the transmission. MSG 3 acts as a random access procedure for RRC connection establishment (re-establishment).

Alternatively, when the terminal finds that the authorized TB data amount is 10 bytes, 10 bytes is smaller than the data amount of the data to be transmitted. Then, the terminal multiplexes 10 bytes. Specifically, the terminal can multiplex terminal identification information, routing information of the core network, BSR MAC control element, and the application layer from the application layer in strict descending priority order. The traffic data packet, until the UL grant is exhausted, the BSR indicates 6 bytes of the remaining data (1 byte is used to report the BSR), the terminal stores the MAC PDU in the MSG 3 and transmits the MSG 3 in the allocated UL resource .

If the base station assigns a terminal a UL grant less than its request, the base station will transmit an additional UL grant to the terminal for the remaining data transfer after the terminal has resolved the contention resolution. The amount of the additional authorization data is allocated according to the amount of BSR data reported by the terminal. For example, the base station allocates one TB of data equal to 10 bytes to schedule UL grant to the terminal, and the terminal's request is 14<BS<=17 bytes, and the base station allocates less authorization than the terminal's request. At this time, the base station allocates one. Additional UL license. The amount of the additional UL grant data is allocated according to the amount of BSR data reported by the terminal. For example, the base station reports a 6-byte BSR in the transmitted MSG 3 message, and the base station obtains the MSG 3 information by decoding, and allocates an additional TB data amount to the terminal according to the indicated data amount of the BSR in the MSG 3. UL grant of bytes.

After the terminal successfully competes for resolution, it can be assumed that all transmitted data has been successfully decoded by the terminal. If the terminal has transmitted all data packets, the terminal assumes that all data has been successfully decoded and returns to the idle mode. Alternatively, after the terminal successfully resolves the dispute, if the terminal receives an additional UL grant within the additional UL grant timer, the terminal may transmit the remaining data (e.g., 6 bytes of data) using the UL resource. Alternatively, if there is residual data at the terminal, but no additional UL grant is received from the base station within the additional UL grant timer, the terminal may retry the random access procedure.

The base station can receive the remaining data using the scheduled UL resources after transmitting the additional UL grant. Successful decoding number Thereafter, the base station can transmit an acknowledgement (Ack) message to the terminal, combine the remaining data with the previously received transmitted data, and pass the traffic data packet to the appropriate server through the serving gateway.

A person skilled in the art can understand that the above embodiments are only examples and do not constitute a limitation of the present invention. Those skilled in the art can make equal variations and modifications of the embodiments of the present application without departing from the spirit of the present invention. The claims are subject to.

Claims

Claim

A data transmission method, comprising:

The terminal receives the broadcast information from the base station, where the broadcast information includes at least one specific resource pool and at least one non-specific resource pool;

When the terminal meets the at least one condition, the terminal uses the at least one specific resource pool to perform a random access procedure for transmitting data.

The data transmission method according to claim 1, wherein the at least one specific resource pool and the at least one non-specific resource pool are divided into a set of different prefix sequences, or a set of different synthesized time-frequency domain resource blocks, or A collection of different prefix sequences and composite time-frequency domain resource blocks.

The data transmission method according to claim 1, wherein the at least one specific resource pool is used for a random access procedure for transmitting traffic data without a radio resource control connection, and the at least one non-specific resource pool is the terminal A random access procedure for implementing a radio resource control connection setup/reestablishment procedure.

The data transmission method according to claim 1, wherein the at least one condition is predefined in a technical specification to support traffic data transmission without a radio resource control connection.

The data transmission method according to claim 1, wherein the at least one condition comprises at least one of the following conditions:

The traffic data packet from an application layer is greater than zero;

The data to be transmitted at the terminal is less than a threshold;

The channel condition is better than a threshold;

The delay requirement is less than a threshold;

The expected data arrival interval is greater than a threshold.

The data transmission method according to claim 5, wherein the data to be transmitted includes at least terminal identification information, routing information of a core network, and a traffic data packet from the application layer.

The data transmission method according to claim 1, further comprising: determining, by the terminal, whether the at least one condition is met, and if the at least one condition is met, selecting the at least one specific resource pool to establish a wireless resource-free resource. Controls the flow of traffic data for the connection.

The data transmission method according to claim 7, further comprising: determining, by the terminal, whether the condition is met, and if the at least one condition is not met, establishing a traffic data transmission of the RRC connection.

A data transmission method, comprising:

The terminal receives broadcast information from the base station, where the broadcast information includes at least one specific resource pool and at least one a non-specific resource pool, wherein the at least one specific resource pool includes at least one resource group;

And transmitting, by the terminal, a prefix sequence to the base station on the time-frequency domain resource block, wherein the prefix sequence and the at least one of the time-frequency domain resource blocks are selected from the at least one resource group in the at least one specific resource pool.

The data transmission method according to claim 9, wherein the transmitting the prefix sequence to the base station on the time-frequency domain resource block through the terminal further comprises:

The terminal determines whether the condition for using a specific resource pool is met.

The data transmission method according to claim 10, wherein the condition for using the specific resource pool is at least one of the following conditions:

The traffic data packet from an application layer is greater than zero;

The threshold value of the data to be transmitted at the terminal;

Channel threshold condition;

Delay demand threshold condition;

The expected data arrives at the interval threshold condition.

The data transmission method according to claim 9, wherein the transmitting, by the terminal, the prefix sequence to the base station on the time-frequency domain resource block further comprises:

Calculating the amount of data of the data to be transmitted by the terminal;

Matching the calculated amount of data to the data level; and

A resource group is selected from the particular resource pool according to a predefined mapping rule, wherein the resource group corresponds to a data volume level.

The data transmission method according to claim 9, wherein before the transmitting the prefix sequence to the base station on the time-frequency domain resource block, the method further comprises:

Calculating channel conditions by the terminal;

Comparing the calculated channel condition to a threshold; and

A set of resource groups is selected from the particular resource pool based on channel conditions and predefined mapping rules.

The data transmission method according to claim 12, wherein the data to be transmitted includes at least terminal identification information, routing information of a core network, and traffic data packets from an application layer.

The data transmission method according to claim 9, wherein:

The at least one specific resource pool is used for data transmission without a radio resource control connection.

The data transmission method according to claim 9, wherein after transmitting the prefix sequence to the base station on the time-frequency domain resource block, the method further comprises: The terminal receives and decodes the random access response, and obtains an uplink grant in the random access response; and the terminal determines whether the data size of the authorized transport block is greater than or equal to the data amount of the data to be transmitted. The data transmission method according to claim 16, wherein the uplink grant in the random access response is received by the base station by receiving the prefix sequence in the time-frequency domain resource block, according to the time-frequency resource block, And the data volume level corresponding to the resource group in which the prefix sequence is located determines the amount of data that can be transmitted by the allocated uplink grant.

The data transmission method according to claim 16, wherein the terminal determines whether the data size of the authorized transport block is greater than or equal to the data amount of the data to be transmitted.

When the data size of the authorized transport block is greater than or equal to the data amount of the data to be transmitted, the terminal transmits the data to be transmitted in the uplink resource indicated by the uplink grant.

The data transmission method according to claim 16, wherein the determining whether the data size of the authorized transport block is greater than or equal to the data amount of the data to be transmitted further comprises:

When the data size of the authorized transport block is greater than or equal to the data amount of the data to be transmitted, the terminal multiplexes a plurality of media access control service data units in the medium access control packet data unit, where the The media access control packet data unit includes the band transmission data;

The terminal stores the media access control packet data unit in a scheduled transmission third message buffer, and transmits a third message in the allocated uplink resource.

The data transmission method according to claim 16, wherein the terminal determines whether the data size of the authorized transport block is greater than or equal to the data amount of the data to be transmitted, and further includes:

When the amount of data of the authorized transport block is less than the amount of data of the data to be transmitted, the terminal retry the random access procedure.

When the data size of the authorized transport block is smaller than the data amount of the data to be transmitted, the terminal triggers the buffer status report to transmit the data to be transmitted in the medium access control packet data unit with strict decrement priority until The uplink grant is exhausted; and

The medium access control packet data unit is stored in a third message by the terminal, and the third message is transmitted to the base station in the allocated uplink resource.

The data transmission method according to claim 21, wherein the data to be transmitted comprises: terminal identification information, routing information of a core network, buffer status report medium access control control element, and traffic data from an application layer. Packet.

The data transmission method according to claim 21, further comprising:

The terminal stores the media access control packet data unit in a third message;

After the third message is transmitted to the base station in the allocated uplink resource, the terminal receives and decodes the contention resolution;

The terminal receives an additional uplink grant from the base station;

The terminal transmits remaining data on the additional uplink resource indicated by the additional uplink grant, wherein the remaining data is the amount of data of the authorized transport block minus the amount of the uplink grant that was transmitted when the uplink grant was exhausted data.

The data transmission method according to claim 23, wherein after transmitting the remaining data on the additional uplink resource indicated by the additional uplink grant, the method further comprises:

The terminal receives an acknowledgment message from the base station for confirming the remaining data transmission.

The data transmission method according to claim 21, further comprising:

The terminal transmits the third message to the base station in the allocated uplink resource;

The terminal turns on an additional uplink grant timer.

The data transmission method according to claim 25, further comprising:

If the additional uplink grant timer expires, the terminal re-attempts the random access procedure.